Which “Untouched” Gen 1 Pokémon are Still the Most Useful?

If a Pokémon is around is long enough it's likely to get some kind of update, whether that be a full-blown evolution, or just a regional form, or a temporary power-up in battle. And often these steps are praised by fans, however there are Pokémon that date back all the way to the beginning that have had none of this special treatment, yet they can still hold their own against the newly empowered options, so let's which Kanto Pokémon still work all these years later! (And yes, I'm counting Toedscool as an update even though they're technically classified differently...)